diff -r 6641e941ef1e -r ff1a9aa48cfd app/django/contrib/gis/geos/coordseq.py --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/app/django/contrib/gis/geos/coordseq.py Tue Oct 14 16:00:59 2008 +0000 @@ -0,0 +1,164 @@ +""" + This module houses the GEOSCoordSeq object, which is used internally + by GEOSGeometry to house the actual coordinates of the Point, + LineString, and LinearRing geometries. +""" +from ctypes import c_double, c_uint, byref +from types import ListType, TupleType +from django.contrib.gis.geos.error import GEOSException, GEOSIndexError +from django.contrib.gis.geos.libgeos import CS_PTR, HAS_NUMPY +from django.contrib.gis.geos.prototypes import cs_clone, cs_getdims, cs_getordinate, cs_getsize, cs_setordinate +if HAS_NUMPY: from numpy import ndarray + +class GEOSCoordSeq(object): + "The internal representation of a list of coordinates inside a Geometry." + + #### Python 'magic' routines #### + def __init__(self, ptr, z=False): + "Initializes from a GEOS pointer." + if not isinstance(ptr, CS_PTR): + raise TypeError('Coordinate sequence should initialize with a CS_PTR.') + self._ptr = ptr + self._z = z + + def __iter__(self): + "Iterates over each point in the coordinate sequence." + for i in xrange(self.size): + yield self[i] + + def __len__(self): + "Returns the number of points in the coordinate sequence." + return int(self.size) + + def __str__(self): + "Returns the string representation of the coordinate sequence." + return str(self.tuple) + + def __getitem__(self, index): + "Returns the coordinate sequence value at the given index." + coords = [self.getX(index), self.getY(index)] + if self.dims == 3 and self._z: + coords.append(self.getZ(index)) + return tuple(coords) + + def __setitem__(self, index, value): + "Sets the coordinate sequence value at the given index." + # Checking the input value + if isinstance(value, (ListType, TupleType)): + pass + elif HAS_NUMPY and isinstance(value, ndarray): + pass + else: + raise TypeError('Must set coordinate with a sequence (list, tuple, or numpy array).') + # Checking the dims of the input + if self.dims == 3 and self._z: + n_args = 3 + set_3d = True + else: + n_args = 2 + set_3d = False + if len(value) != n_args: + raise TypeError('Dimension of value does not match.') + # Setting the X, Y, Z + self.setX(index, value[0]) + self.setY(index, value[1]) + if set_3d: self.setZ(index, value[2]) + + #### Internal Routines #### + def _checkindex(self, index): + "Checks the given index." + sz = self.size + if (sz < 1) or (index < 0) or (index >= sz): + raise GEOSIndexError('invalid GEOS Geometry index: %s' % str(index)) + + def _checkdim(self, dim): + "Checks the given dimension." + if dim < 0 or dim > 2: + raise GEOSException('invalid ordinate dimension "%d"' % dim) + + @property + def ptr(self): + """ + Property for controlling access to coordinate sequence pointer, + preventing attempted access to a NULL memory location. + """ + if self._ptr: return self._ptr + else: raise GEOSException('NULL coordinate sequence pointer encountered.') + + #### Ordinate getting and setting routines #### + def getOrdinate(self, dimension, index): + "Returns the value for the given dimension and index." + self._checkindex(index) + self._checkdim(dimension) + return cs_getordinate(self.ptr, index, dimension, byref(c_double())) + + def setOrdinate(self, dimension, index, value): + "Sets the value for the given dimension and index." + self._checkindex(index) + self._checkdim(dimension) + cs_setordinate(self.ptr, index, dimension, value) + + def getX(self, index): + "Get the X value at the index." + return self.getOrdinate(0, index) + + def setX(self, index, value): + "Set X with the value at the given index." + self.setOrdinate(0, index, value) + + def getY(self, index): + "Get the Y value at the given index." + return self.getOrdinate(1, index) + + def setY(self, index, value): + "Set Y with the value at the given index." + self.setOrdinate(1, index, value) + + def getZ(self, index): + "Get Z with the value at the given index." + return self.getOrdinate(2, index) + + def setZ(self, index, value): + "Set Z with the value at the given index." + self.setOrdinate(2, index, value) + + ### Dimensions ### + @property + def size(self): + "Returns the size of this coordinate sequence." + return cs_getsize(self.ptr, byref(c_uint())) + + @property + def dims(self): + "Returns the dimensions of this coordinate sequence." + return cs_getdims(self.ptr, byref(c_uint())) + + @property + def hasz(self): + """ + Returns whether this coordinate sequence is 3D. This property value is + inherited from the parent Geometry. + """ + return self._z + + ### Other Methods ### + def clone(self): + "Clones this coordinate sequence." + return GEOSCoordSeq(cs_clone(self.ptr), self.hasz) + + @property + def kml(self): + "Returns the KML representation for the coordinates." + # Getting the substitution string depending on whether the coordinates have + # a Z dimension. + if self.hasz: substr = '%s,%s,%s ' + else: substr = '%s,%s,0 ' + return '%s' % \ + ''.join([substr % self[i] for i in xrange(len(self))]).strip() + + @property + def tuple(self): + "Returns a tuple version of this coordinate sequence." + n = self.size + if n == 1: return self[0] + else: return tuple([self[i] for i in xrange(n)])